Method for providing an operable filter system for filtering particles out of a beam of radiation, filter system, apparatus and lithographic apparatus comprising the filter system

Abstract

A method for providing an operable filter system for filtering particles out of a beam of radiation in lithography is disclosed. The method includes providing a slack foil or wire for intercepting the particles, mounting at least a first point or side of the foil or wire to a first position of a mounting assembly, and substantially stretching the slack foil or wire at least within the beam of radiation, substantially parallel to a direction in which the radiation propagates.

1. A method for providing an operable filter system for filtering particles out of a beam of radiation in lithography, the method comprising:
 providing a flexible foil or wire for intercepting the particles; 
 mounting at least a first point or side of the foil or wire to a first position of a mounting assembly; and 
 substantially stretching the flexible foil or wire at least within the beam of radiation, substantially parallel to a direction in which the radiation propagates. 
 
   
   
     2. A method according to  claim 1 , further comprising mounting a second point or side of the foil or wire to a second position of the mounting assembly such that a distance between the first and second position can be modified. 
   
   
     3. A method according to  claim 2 , further comprising stretching the foil or wire between the first and second positions. 
   
   
     4. A method according to  claim 1 , wherein the foil or wire, at least within the beam, is stretched so as to substantially extend in a virtual flat plane. 
   
   
     5. A method according to  claim 4 , wherein the virtual plane intersects the radiation source. 
   
   
     6. A method according to  claim 1 , wherein the foil or wire is stretched by a force substantially acting in a direction in which the foil or wire extends. 
   
   
     7. A method according to  claim 6 , wherein the force is provided by a centrifugal force on the foil or wire. 
   
   
     8. A method according to  claim 7 , further comprising arranging a mass on the foil or wire for increasing the centrifugal force. 
   
   
     9. A method according to  claim 1 , further comprising translating and/or rotating the foil or wire, at least within the beam. 
   
   
     10. A method according to  claim 1 , further comprising providing a plurality of flexible foils or wires and substantially stretching the flexible foils or wires at least within the beam of radiation. 
   
   
     11. A method according to  claim 1 , wherein the foil or wire includes a flexible tape or thread. 
   
   
     12. A method according to  claim 1 , further comprising generating the beam of radiation and the particles using a radiation source. 
   
   
     13. A method according to  claim 1 , further comprising processing the radiation using a processing system. 
   
   
     14. A filter system for filtering particles out of a beam of radiation, the filter system being suited for use in lithography, the filter system comprising:
 a flexible foil or wire configured to intercept the particles, 
 at least a first point or side of the foil or wire being mounted to a first position of a mounting assembly, and 
 the flexible foil or wire being arranged to be stretched substantially parallel to a direction in which the radiation propagates, at least within the beam of radiation. 
 
   
   
     15. A filter system according to  claim 14 , wherein the mounting assembly has at least two spatially separated positions configured to mount the foil or wire between the at least two positions such that a distance between the at least two positions can be modified. 
   
   
     16. A filter system according to  claim 15 , wherein the foil or wire is stretched between the at least two positions. 
   
   
     17. A filter system according to  claim 14 , wherein the foil or wire, at least within the beam, is stretched so as to substantially extend in a virtual flat plane. 
   
   
     18. A filter system according to  claim 14 , wherein the foil or wire is stretched by a force substantially acting in a direction in which the foil or wire extends. 
   
   
     19. A filter system according to  claim 18 , wherein the force is provided by a centrifugal force on the foil or wire. 
   
   
     20. A filter system according to  claim 19 , wherein a mass is arranged on the foil or wire for increasing the centrifugal force. 
   
   
     21. A filter system according to  claim 14 , wherein the foil or wire is translated and/or rotated, at least within the beam. 
   
   
     22. A filter system according to  claim 14 , further comprising a plurality of flexible foils or wires, wherein the flexible foils or wires are substantially stretched. 
   
   
     23. A filter system according to  claim 14 , wherein the foil or wire includes a flexible tape or thread. 
   
   
     24. An apparatus suited for use in lithography, the apparatus comprising:
 a radiation source, 
 a processing system configured to process the radiation from the radiation source, and 
 a filter system configured to filter particles out of radiation propagating from the radiation source towards the processing system through a predetermined cross section of the radiation as emitted by the radiation source, the filter system including a flexible foil or wire configured to intercept the particles, at least a first point or side of the foil or wire being mounted to a first position of a mounting assembly, the flexible foil or wire being arranged to be stretched substantially parallel to a direction in which the radiation propagates, at least within the beam of radiation. 
 
   
   
     25. An apparatus according to  claim 24 , wherein the mounting assembly has at least two spatially separated positions configured to mount the foil or wire between the at least two positions such that a distance between the at least two positions can be modified. 
   
   
     26. An apparatus according to  claim 25 , wherein the foil or wire is stretched between the at least two positions. 
   
   
     27. An apparatus according to  claim 24 , wherein the foil or wire, at least within the beam, is stretched so as to substantially extend in a virtual flat plane. 
   
   
     28. An apparatus according to  claim 24 , wherein the foil or wire is stretched by a force substantially acting in a direction in which the foil or wire extends. 
   
   
     29. An apparatus according to  claim 28 , wherein the force is provided by a centrifugal force on the foil or wire. 
   
   
     30. An apparatus according to  claim 29 , wherein a mass is arranged on the foil or wire for increasing the centrifugal force. 
   
   
     31. An apparatus according to  claim 24 , wherein the foil or wire is translated and/or rotated, at least within the beam. 
   
   
     32. An apparatus according to  claim 24 , wherein the filter system further includes a plurality of flexible foils or wires, wherein the flexible foils or wires are substantially stretched. 
   
   
     33. An apparatus according to  claim 24 , wherein the foil or wire includes a flexible tape or thread. 
   
   
     34. A lithographic apparatus comprising:
 a radiation system configured to condition a radiation beam, the radiation system including:
 (a) a radiation source, 
 (b) a processing system configured to process the radiation from the radiation source, and 
 (c) a filter system configured to filter particles out of radiation propagating from the radiation source towards the processing system through a predetermined cross section of the radiation as emitted by the radiation source, the filter system including a flexible foil or wire configured to intercept the particles, at least a first point or side of the foil or wire being mounted to a first position of a mounting assembly, the flexible foil or wire being arranged to be stretched substantially parallel to a direction in which the radiation propagates, at least within the beam of radiation; and 
 
 a projection system configured to project the radiation beam onto a substrate. 
 
   
   
     35. A lithographic apparatus according to  claim 34 , wherein the mounting assembly has at least two spatially separated positions configured to mount the foil or wire between the at least two positions such that a distance between the at least two positions can be modified. 
   
   
     36. A lithographic apparatus according to  claim 35 , wherein the foil or wire is stretched between the at least two positions. 
   
   
     37. A lithographic apparatus according to  claim 34 , wherein the foil or wire, at least within the beam, is stretched so as to substantially extend in a virtual flat plane. 
   
   
     38. A lithographic apparatus according to  claim 34 , wherein the foil or wire is stretched by a force substantially acting in a direction in which the foil or wire extends. 
   
   
     39. A lithographic apparatus according to  claim 38 , wherein the force is provided by a centrifugal force on the foil or wire. 
   
   
     40. A lithographic apparatus according to  claim 39 , wherein a mass is arranged on the foil or wire for increasing the centrifugal force. 
   
   
     41. A lithographic apparatus according to  claim 34 , wherein the foil or wire is translated and/or rotated, at least within the beam. 
   
   
     42. A lithographic apparatus according to  claim 34 , wherein the filter system further includes a plurality of flexible foils or wires, wherein the flexible foils or wires are substantially stretched. 
   
   
     43. A lithographic apparatus according to  claim 34 , wherein the foil or wire includes a flexible tape or thread.